Revert the changes in event_accumulator. (#6013)

Reverts changes in event_accumulator from #5998, this caused
internal breakage, where users directly access `EventAccumulator` and unpack the events like tuples.

Author: yatbear

tensorboard/backend/event_processing/event_accumulator.py

@@ -15,11 +15,8 @@
 """Takes a generator of values, and accumulates them for a frontend."""
 
 import collections
-import dataclasses
 import threading
 
-from typing import Sequence, Tuple
-
 from tensorboard.backend.event_processing import directory_watcher
 from tensorboard.backend.event_processing import event_file_loader
 from tensorboard.backend.event_processing import io_wrapper
@@ -30,137 +27,47 @@
 from tensorboard.compat.proto import event_pb2
 from tensorboard.compat.proto import graph_pb2
 from tensorboard.compat.proto import meta_graph_pb2
-from tensorboard.compat.proto import tensor_pb2
 from tensorboard.plugins.distribution import compressor
 from tensorboard.util import tb_logging
 
 
 logger = tb_logging.get_logger()
 
-
-@dataclasses.dataclass(frozen=True)
-class ScalarEvent:
-    """Contains information of a scalar event.
-
-    Attributes:
-      wall_time: Timestamp of the event in seconds.
-      step: Global step of the event.
-      value: A float or int value of the scalar.
-    """
-
-    wall_time: float
-    step: int
-    value: float
-
-
-@dataclasses.dataclass(frozen=True)
-class CompressedHistogramEvent:
-    """Contains information of a compressed histogram event.
-
-    Attributes:
-      wall_time: Timestamp of the event in seconds.
-      step: Global step of the event.
-      compressed_histogram_values: A sequence of tuples of basis points and
-        associated values in a compressed histogram.
-    """
-
-    wall_time: float
-    step: int
-    compressed_histogram_values: Sequence[Tuple[float, float]]
-
-
-@dataclasses.dataclass(frozen=True)
-class HistogramValue:
-    """Holds the information of the histogram values.
-
-    Attributes:
-      min: A float or int min value.
-      max: A float or int max value.
-      num: Total number of values.
-      sum: Sum of all values.
-      sum_squares: Sum of squares for all values.
-      bucket_limit: Upper values per bucket.
-      bucket: Numbers of values per bucket.
-    """
-
-    min: float
-    max: float
-    num: int
-    sum: float
-    sum_squares: float
-    bucket_limit: Sequence[float]
-    bucket: Sequence[int]
-
-
-@dataclasses.dataclass(frozen=True)
-class HistogramEvent:
-    """Contains information of a histogram event.
-
-    Attributes:
-      wall_time: Timestamp of the event in seconds.
-      step: Global step of the event.
-      histogram_value: Information of the histogram values.
-    """
-
-    wall_time: float
-    step: int
-    histogram_value: HistogramValue
-
-
-@dataclasses.dataclass(frozen=True)
-class ImageEvent:
-    """Contains information of an image event.
-
-    Attributes:
-      wall_time: Timestamp of the event in seconds.
-      step: Global step of the event.
-      encoded_image_string: Image content encoded in bytes.
-      width: Width of the image.
-      height: Height of the image.
-    """
-
-    wall_time: float
-    step: int
-    encoded_image_string: bytes
-    width: int
-    height: int
-
-
-@dataclasses.dataclass(frozen=True)
-class AudioEvent:
-    """Contains information of an audio event.
-
-    Attributes:
-      wall_time: Timestamp of the event in seconds.
-      step: Global step of the event.
-      encoded_audio_string: Audio content encoded in bytes.
-      content_type: A string describes the type of the audio content.
-      sample_rate: Sample rate of the audio in Hz. Must be positive.
-      length_frames: Length of the audio in frames (samples per channel).
-    """
-
-    wall_time: float
-    step: int
-    encoded_audio_string: bytes
-    content_type: str
-    sample_rate: float
-    length_frames: int
-
-
-@dataclasses.dataclass(frozen=True)
-class TensorEvent:
-    """A tensor event.
-
-    Attributes:
-      wall_time: Timestamp of the event in seconds.
-      step: Global step of the event.
-      tensor_proto: A `TensorProto`.
-    """
-
-    wall_time: float
-    step: int
-    tensor_proto: tensor_pb2.TensorProto
-
+namedtuple = collections.namedtuple
+ScalarEvent = namedtuple("ScalarEvent", ["wall_time", "step", "value"])
+
+CompressedHistogramEvent = namedtuple(
+    "CompressedHistogramEvent",
+    ["wall_time", "step", "compressed_histogram_values"],
+)
+
+HistogramEvent = namedtuple(
+    "HistogramEvent", ["wall_time", "step", "histogram_value"]
+)
+
+HistogramValue = namedtuple(
+    "HistogramValue",
+    ["min", "max", "num", "sum", "sum_squares", "bucket_limit", "bucket"],
+)
+
+ImageEvent = namedtuple(
+    "ImageEvent",
+    ["wall_time", "step", "encoded_image_string", "width", "height"],
+)
+
+AudioEvent = namedtuple(
+    "AudioEvent",
+    [
+        "wall_time",
+        "step",
+        "encoded_audio_string",
+        "content_type",
+        "sample_rate",
+        "length_frames",
+    ],
+)
+
+TensorEvent = namedtuple("TensorEvent", ["wall_time", "step", "tensor_proto"])
 
 ## Different types of summary events handled by the event_accumulator
 SUMMARY_TYPES = {
@@ -757,8 +664,7 @@ def _CheckForOutOfOrderStepAndMaybePurge(self, event):
             self.most_recent_step = event.step
             self.most_recent_wall_time = event.wall_time
 
-    def _ConvertHistogramProtoToPopo(self, histo):
-        """Converts histogram proto to Python object."""
+    def _ConvertHistogramProtoToTuple(self, histo):
         return HistogramValue(
             min=histo.min,
             max=histo.max,
@@ -771,7 +677,7 @@ def _ConvertHistogramProtoToPopo(self, histo):
 
     def _ProcessHistogram(self, tag, wall_time, step, histo):
         """Processes a proto histogram by adding it to accumulated state."""
-        histo = self._ConvertHistogramProtoToPopo(histo)
+        histo = self._ConvertHistogramProtoToTuple(histo)
         histo_ev = HistogramEvent(wall_time, step, histo)
         self.histograms.AddItem(tag, histo_ev)
         self.compressed_histograms.AddItem(